Hide std::vector roots of Exp.

git-svn-id: http://svn.drobilla.net/resp/tuplr@178 ad02d1e2-f140-0410-9f75-f8b11f17cedd

2 files changed, 29 insertions, 15 deletions

diff --git a/src/parse.cpp b/src/parse.cpp
index e37f095..a6af50c 100644
--- a/src/parse.cpp
+++ b/src/parse.cpp
@@ -31,22 +31,27 @@ using namespace std;
 inline SExp
 macDef(PEnv& penv, const SExp& exp)
 {
-	THROW_IF(exp.size() < 3, exp.loc, "[MAC] `def' requires at least 2 arguments")
-	if (exp.at(1).type == SExp::ATOM) {
+	SExp::const_iterator i = exp.begin();
+	THROW_IF(i == exp.end(), exp.loc, "Unexpected end of `def' macro call");
+	const SExp& name = *(++i);
+	THROW_IF(i == exp.end(), name.loc, "Unexpected end of `def' macro call");
+	if (name.type == SExp::ATOM) {
 		return exp;
 	} else {
 		// (def (f x) y) => (def f (fn (x) y))
 		SExp argsExp(exp.loc);
-		for (size_t i = 1; i < exp.at(1).size(); ++i)
-			argsExp.push_back(exp.at(1).at(i));
-		SExp fnExp(exp.at(2).loc);
-		fnExp.push_back(SExp(exp.at(2).loc, "fn"));
+		SExp::const_iterator j = name.begin();
+		for (++j; j != name.end(); ++j)
+			argsExp.push_back(*j);
+		const SExp& body = *(++i);
+		SExp fnExp(body.loc);
+		fnExp.push_back(SExp(body.loc, "fn"));
 		fnExp.push_back(argsExp);
-		for (size_t i = 2; i < exp.size(); ++i)
-			fnExp.push_back(exp.at(i));
+		for (; i != exp.end(); ++i)
+			fnExp.push_back(*i);
 		SExp ret(exp.loc);
-		ret.push_back(exp.at(0));
-		ret.push_back(exp.at(1).at(0));
+		ret.push_back(exp.front());
+		ret.push_back(name.front());
 		ret.push_back(fnExp);
 		return ret;
 	}
@@ -74,9 +79,8 @@ parseLiteral(PEnv& penv, const SExp& exp, void* arg)
 inline AST*
 parseFn(PEnv& penv, const SExp& exp, void* arg)
 {
-	THROW_IF(exp.size() < 2,exp.loc, "Missing function parameters and body");
-	THROW_IF(exp.size() < 3, exp.loc, "Missing function body");
-	SExp::const_iterator a = exp.begin(); ++a;
+	SExp::const_iterator a = exp.begin();
+	THROW_IF(++a == exp.end(), exp.loc, "Unexpected end of `fn' form");
 	AFn* ret = tup<AFn>(exp.loc, penv.sym("fn"), new ATuple(penv.parseTuple(*a++)), 0);
 	while (a != exp.end())
 		ret->push_back(penv.parse(*a++));
diff --git a/src/tuplr.hpp b/src/tuplr.hpp
index de025b7..5deff71 100644
--- a/src/tuplr.hpp
+++ b/src/tuplr.hpp
@@ -61,11 +61,21 @@ struct Error {
 	string msg;
 };
 
-/// Expression ::= Atom | (SubExp*)
+/// Expression ::= Atom | (Expression*)
 template<typename Atom>
-struct Exp : public std::vector< Exp<Atom> > {
+struct Exp : private std::vector< Exp<Atom> > {
 	Exp(Cursor c)                : type(LIST), loc(c)          {}
 	Exp(Cursor c, const Atom& a) : type(ATOM), loc(c), atom(a) {}
+
+	void push_back(const Exp<Atom>& exp) { vector< Exp<Atom> >::push_back(exp); }
+
+	bool             empty() const { return vector< Exp<Atom> >::empty(); }
+	const Exp<Atom>& front() const { return vector< Exp<Atom> >::front(); }
+
+	typedef typename vector< Exp<Atom> >::const_iterator const_iterator;
+	const_iterator begin() const { return vector< Exp<Atom> >::begin(); }
+	const_iterator end()   const { return vector< Exp<Atom> >::end(); }
+
 	enum { ATOM, LIST } type;
 	Cursor              loc;
 	Atom                atom;